Board Thread:General Discussion/@comment-25235588-20171014004107/@comment-31267872-20171014233228

Okay, so...

Mimikyu: Go into Gale Forest at night. Find a wild Pikachu. This may be hard because Pikachu only has a 3% chance of appearing. Once you find a wild Pikachu at night, the game will say it is acting weirdly, and it will change into Mimikyu.

Marshadow: A portal can spawn at Routes 9, 10, 11, 12, 15, Cosmeos Valley, and Lagoona Lake. Go into the portal. Face your character where it is not facing the shadow of Marshadow. When Marshadow's eyes pop up, click on them.

Portal Locations

Route 9: Near the entrance.

Route 10: Somewhere near the windmill.

Route 11: Somewhere in Route 11.

Route 12: Near Route 13 entrance, at the tree with a note.

Route 15: Go to an ice waterfall, near a sign that says "Route 217"

Cosmeos Valley: Fly to Port Decca, get into Cosmeos Valley and keep walking straight until you get pass the laboratory.

Lagoona Lake: Somewhere in Lagoona Lake.

Hope this helped!

(Source: CharlesW9's blog)